Java: Support String.formatted in the format string queries.

Author: aschackmull

java/ql/src/semmle/code/java/StringFormat.qll

@@ -22,6 +22,7 @@ class StringFormatMethod extends FormatMethod {
   StringFormatMethod() {
     (
       this.hasName("format") or
+      this.hasName("formatted") or
       this.hasName("printf") or
       this.hasName("readLine") or
       this.hasName("readPassword")
@@ -38,6 +39,8 @@ class StringFormatMethod extends FormatMethod {
   override int getFormatStringIndex() {
     result = 0 and this.getSignature() = "format(java.lang.String,java.lang.Object[])"
     or
+    result = -1 and this.getSignature() = "formatted(java.lang.Object[])"
+    or
     result = 0 and this.getSignature() = "printf(java.lang.String,java.lang.Object[])"
     or
     result = 1 and
@@ -91,6 +94,11 @@ class FmtSyntax extends TFmtSyntax {
   predicate isLogger() { this = TFmtLogger() }
 }
 
+private Expr getArgumentOrQualifier(Call c, int i) {
+  result = c.getArgument(i) or
+  result = c.getQualifier() and i = -1
+}
+
 /**
  * Holds if `c` wraps a call to a `StringFormatMethod`, such that `fmtix` is
  * the index of the format string argument to `c` and the following and final
@@ -111,7 +119,7 @@ private predicate formatWrapper(Callable c, int fmtix, FmtSyntax syntax) {
       or
       fmtcall.getCallee().(LoggerFormatMethod).getFormatStringIndex() = i and syntax = TFmtLogger()
     ) and
-    fmtcall.getArgument(i) = fmt.getAnAccess() and
+    getArgumentOrQualifier(fmtcall, i) = fmt.getAnAccess() and
     fmtcall.getArgument(i + 1) = args.getAnAccess()
   )
 }
@@ -155,7 +163,7 @@ class FormattingCall extends Call {
   }
 
   /** Gets the argument to this call in the position of the format string */
-  Expr getFormatArgument() { result = this.getArgument(this.getFormatStringIndex()) }
+  Expr getFormatArgument() { result = getArgumentOrQualifier(this, this.getFormatStringIndex()) }
 
   /** Gets an argument to be formatted. */
   Expr getAnArgumentToBeFormatted() {

java/ql/test/query-tests/StringFormat/A.java

@@ -85,4 +85,9 @@ void g(boolean b, int i) {
     String.format("%s%s", a2); // ok
     String.format("%s", a2); // unused
   }
+
+  void formatted() {
+    "%s%s".formatted(""); // missing
+    "%s".formatted("", ""); // unused
+  }
 }

java/ql/test/query-tests/StringFormat/MissingFormatArg.expected

@@ -17,3 +17,4 @@
 | A.java:74:5:74:47 | format(...) | This format call refers to 2 argument(s) but only supplies 1 argument(s). |
 | A.java:79:5:79:31 | format(...) | This format call refers to 3 argument(s) but only supplies 2 argument(s). |
 | A.java:84:5:84:31 | format(...) | This format call refers to 3 argument(s) but only supplies 2 argument(s). |
+| A.java:90:5:90:24 | formatted(...) | This format call refers to 2 argument(s) but only supplies 1 argument(s). |

java/ql/test/query-tests/StringFormat/UnusedFormatArg.expected

@@ -9,3 +9,4 @@
 | A.java:76:5:76:57 | format(...) | This format call refers to 2 argument(s) but supplies 3 argument(s). |
 | A.java:81:5:81:27 | format(...) | This format call refers to 1 argument(s) but supplies 2 argument(s). |
 | A.java:86:5:86:27 | format(...) | This format call refers to 1 argument(s) but supplies 2 argument(s). |
+| A.java:91:5:91:26 | formatted(...) | This format call refers to 1 argument(s) but supplies 2 argument(s). |

java/ql/test/query-tests/StringFormat/options

@@ -0,0 +1 @@
+//semmle-extractor-options: --javac-args --enable-preview -source 14 -target 14